Vocabulary

Introduction

Geographic Information Science

Uses computers and satellite imagery to capture, store, manipulate, analyze, manage, and present spatial data. Sometimes referred to as geographic information systems.

1.1 Geography – The Science of Where and Why

Geographic Perspective

Spatially viewing the world, as a geographer.

Geography

The study of natural and human-constructed phenomena relative to a spatial dimension.

1.2 The Geographic Perspective

Mental Maps

Maps of our environment that are stored in our brains.

1.3 The Power of Maps

Absolute Location

A location that use some type of reference system to define it’s position on the earth’s surface.

Choropleth Map

A thematic map that uses tones or colors to represent spatial data as average values per unit area.

Dasymetric Map

A thematic map that is an alternative to a choropleth map, but instead of mapping the data so that the region appears uniform, ancillary information is used to model the internal distribution of the data.

Direction

The position of something relative to something else, usually along a line.

Distance

The degree or amount of separation between locations; can be measured in nominal or absolute terms with various units.

Dot Map

A thematic map that uses a dot symbol to show the presence of a feature or phenomenon; relies on a visual scatter to show a spatial pattern.

Geocoding

A process to determine the geographic coordinates of particular street addresses, zip codes, place names, and other geographic data.

Geographic Coordinate System (GCS)

The coordinate system that is most commonly used to define locations on the three-dimensional earth; it is based on a sphere or spheroid, and uses latitude and longitude to determine location.

Geographic Grid System

Parallel and meridian lines combined to form a geographic grid system that allows users to determine their exact location on the planet.

Geographical Information System (GIS)

A computer-based tool used to help people transform geographic data into geographic information.

Global Positioning System (GPS)

A satellite-based navigation system made up of a network of 24 satellites placed into orbit by the U.S. Department of Defense.

Great Circle

Any circle that divides the earth into a circumference of two halves.

International Date Line

The line determines where the new day begins in the world. It is located 180 degrees longitude from the Prime Meridian, in the Pacific Ocean.

Isopleth Map

A thematic map that depicts smooth continuous phenomena such as precipitation or elevation; Also known as contour maps.

Latitude

An angular measurement north or south of the equator relative to a point found at the center of the Earth.

Location

A position on the surface of the earth.

Longitude

The angular measurement east and west of the Prime Meridian.

Map

A graphic representation of the real world.

Navigation

How we move through the environments where we live, work, and play; destination-oriented travel.

Nominal Location

A location simply defined and described by name.

Opisometer

A device uses a small rotating wheel that records the distance traveled.

Parallels

Lines connecting points of the same latitude.

Prime Meridian

A line of longitude that has a value of zero degrees.

Proportional Symbol Map

A thematic map that uses symbols of different sizes to represent data associated with different areas or locations within the map.

Relative Location

Location by defining and describing places in relation to other known locations.

Remote Sensing

The process of gathering data about an area by remotely sensing electromagnetic radiation reflected and emitted from Earth’s surface.

Scale

The ratio between the distance between two locations on a map and the corresponding distance on Earth’s surface.

Small Circles

Circles that cut the earth, but not into equal halves.

Space

A somewhat ambiguous and generic term that is used to denote the general geographic area of interest.

Thematic Maps

Maps concerned with a particular theme or topic of interest, and how things are distributed across space.

Time Zone

A zone where time is measured relative the Coordinated Universal Time (UTC) standard at the Prime Meridian.

Toponymy

The study of place names and their respective history and meanings.

1.4 The Future of GIS

Diffusion

The spreading of something from one place to another; can relate to the physical movement of people or the spread of disease, or the diffusion of ideas, technology, or other intangible phenomena.

Geographic Information Science

Uses computers and satellite imagery to capture, store, manipulate, analyze, manage, and present spatial data. Sometimes referred to as geographic information systems.

Geographic Information Systems (GIS)

A computer-based tool used to help people transform geographic data into geographic information.

Map Projection

A representation of Earth’s surface on a flat plane; The methods and procedures that are used to transform the spherical three-dimensional earth into two-dimensional planar surfaces; Mathematical formulas that are used to translate latitude and longitude on the surface of the earth to x and y coordinates on a plane.

Web GIS

The integration of the vast amounts of content available on the Internet (e.g., text, photographs, video, and music) with geographic information, such as location.

Winkel Tripel Projection

So-named because its creator, Oswald Winkel, sought to minimize three kinds of distortion: area, direction, and distance. The National Geographic Society has used it since 1998 as the standard projection of world maps.